When I wrote "Selection of Pipettes" on the Internet, I also wrote "Operation of Pipettes", and I was fortunately cited several times. Of course, there are more than one person who wrote similar articles on the Internet. But do users attach great importance to this issue? Unfortunately, the answer is no. Quite a lot of people think that the pipette is a very simple instrument, and its operation is also very simple, there is no need to spend a lot of time, and there is no need to take any training courses. In fact? Good pipette operation habits are of great benefit in extending the life of the pipette, improving the accuracy of pipetting and maintaining the health of the user. Let ’s build some common operating habits in the laboratory, but also the ones that are quite wrong. I hope you will not find your shadow in it. First, install the suction head. In the laboratory where pipettes are frequently used, the sound of tapping the tip can often be heard one after another, which adds a bit of music to the boring laboratory life. Upon closer inspection, it turned out that the user was afraid that the pipette tip could not be tightened tightly. After the pipette tip was mounted on the pipette, it was struck a few times in the pipette tip box, hoping to ensure the sealing of the pipette through this impact force. Sex. What is wrong with this operation? First, under the impact of impact, the tip may be deformed and affect the accuracy of pipetting; second, the part of the pipette handle that touches the tip will undergo multiple strong frictions and will It gradually becomes rough and it is difficult to ensure the tightness, and in order to achieve a good tightness, a greater impact force is required, and a vicious cycle begins. Third, the sleeves of small-scale pipettes are relatively thin, and are constantly impacted. Under the devastation, it is likely to become a fishing hook; Fourth, sometimes this impact force is greater than the force that the pipette falls on the ground, and some precision parts in the pipette may be overwhelmed and may strike at any time. Second, the suction angle. In order to facilitate the observation of the sample in the pipette during pipetting, many users will keep the pipette at a 45o inclination or even closer to a horizontal angle during pipetting. But this is wrong again. First, when sampling a sample close to or reaching the maximum volume of the pipette tip, the large angle tilt of the pipette can easily allow the liquid to slip into the pipette handle, thereby contaminating or even corroding the pipette piston. It is easy to cause cross-contamination of the sample; second, the large angle tilt of the pipette will also increase the contact surface of the outer wall of the tip and the liquid, so that when the tip leaves the liquid surface, more liquid remains on the outer wall, which is easy to When the liquid is discharged, it will leave the tip together with the liquid in the tip, thereby reducing the accuracy of the pipetting. For these small liquids (such as 2ul and 10ul), the residual liquid may damage the accuracy. fatal! Third, the speed of aspiration. In the laboratory, it can often be seen that in order to "improve efficiency", the user quickly releases his thumb during aspiration, which causes the liquid to quickly flush into the tip. As everyone knows, this will force the liquid to form a turbulent state after entering the tip, so that for small and medium range pipettes, an invisible vapor mist will be generated and enter the interior of the pipette, for a large range of pipettes You will see the liquid flush directly into the pipette. The end result is contamination or even corrosion of the pipette piston, which can easily cause cross-contamination of the sample and affect accuracy. Fourth, storage. Quite a lot of users will put the pipette directly on the laboratory table after using the pipette, and those who like tidy may put the pipette in the drawer. This is actually not good! During the pipetting operation, it is inevitable that liquid will enter the pipette. In the flat state, these liquids will always remain on the piston and other parts. After accumulating over time, the piston will be contaminated or even corroded. . In the above listed problems, the corrosion of the piston is often mentioned. Some people may say: The piston of the pipette I use is corrosion-resistant! But I still have to remind two points: First, except for a few low-end pipettes that use all-plastic accessories, most pipettes There are metal parts in the piston assembly; second, as long as the piston is contaminated, no matter what the piston material is, there may be a reduction in the internal tightness of the pipette and cross-contamination of the sample. In short, it is necessary for each laboratory to establish and improve SOP (Standard Operating Procedure) used by pipettes, strict management of pipette operations.
Nylon Horse Halter is soft and smooth. Good Horse Halter with durable hardware is a good choice for your horse. We can offer you size of Full, Cob, Pony. Customized color basing on your market's needs. As to hardware, You can choice basic hardware combination or more hardware for convenient use. Nylon horse halter is durable and won't be out of shape.
Nylon Horse Halter Nylon Horse Halter,Reflective Nylon Horse Halter,Waterproof Nylon Horse Halter,Nylon Webbing Horse Halter Hebei Honde Group , https://www.horseequipmentfromchina.com